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Taxonomic Rant (was Re: SERENO'S NEW DINOSAUR PAPER)



At 10:37 AM 7/2/97 -0400, Norm King wrote:
>>Hmmm, perhaps using the type specimen of _I. bernissartensis_, even if 
>it
>>should prove to come from another genus, might be a solution?  (Of 
>course,
>>you lose the English connection, but what can you do?)
>
>If the material from Bernissart turns out to be different from Mantell's 
>Iguanodon, or if Mantell's Iguanodon is based upon plesiomorphic 
>characters, then I. bernissartensis will have to be reassigned to a new 
>genus, will it not, since the original concept will have lost any generic 
>content?

Essentially.  And, in hindsight, there isn't any problem using the type of
_Iguanodon_ to anchor the taxon: although there might be question as to the
interrelationships WITHIN the Iguanodontia, the Weald teeth clearly come
from iguanodontian euornithopod ornithopod ornithischian dinosaurs and not
from any other kind of animal.

>Should we honor a name that may have only historical significance?  If so,
then what >happened to Lagosuchus?

Iguanodon has somewhat greater historical significance than Lagosuchus.
Also, the last word has NOT been written concerning the taxonomic status
Lagosuchus...

>Do we realy need a name for every 
>node and stem,

No, but see below.

>especially when one taxonomist's cladogram may not match 
>another's?

Part of the phylogenetic taxonomic method is that the taxon definitions are
NOT tied into a particular cladogram.  Crocs and birds will always have some
most recent common ancestor: whether Tyrannosaurus, Aetosaurus, Euparkeria,
Homo, or Quercus are descendants of that common ancestor are different
questions.  Membership in the clade Archosauria thus becomes a testable,
repeatable hypothesis.

>I think phylogenetic taxonomy will also 
>end up in chaos unless we back off from proposing ever more terminology 
>that is ever more useless due to its own ever-increasing inertia.

And there's there rub.  Define the utility of terminology.  Is there any
more need people who do not work at a particular part of the tree of life to
learn, memorize, or even USE all that particular taxonomy then there is for
most people to (for example) memorize the names and compositions of ALL (as
in *ALL*) the carbonate minerals?  I can get by fairly well remembering just
a handful of the carbonates, and am unlikely to refer to any of the rarer
ones in class or conversation.  Many on this net will have even less need to
know or use those names.

On the other hand, it is as important to specialists on a particular group
to know more precisely the taxonomic definitions of that branch as it is for
a carbonate petrologist to know the nitty-gritty of their field of
specialization.

Would any of you out there suggest that mineralogists stop naming new
minerals?  Would you have good reason to?

(Also, and this is a general comment to the net.population) some out there
seem to think this sort of taxonomy is unique to dinosaurian (or more
general archosaurian) studies.  If this is your impressino, I strongly
suggest you check out the recent techincal taxonomic literature on any
animal, plant, or fungi group.  I would feel it inappropriate for me to tell
ichthyologists to stop naming all those teleost groups, that not every node
needs a name, etc.)

Sorry for the rant, but I thought it needed saying.  Back to your regularly
scheduled programming.

Thomas R. Holtz, Jr.
Vertebrate Paleontologist     Webpage: http://www.geol.umd.edu
Dept. of Geology              Email:th81@umail.umd.edu
University of Maryland        Phone:301-405-4084
College Park, MD  20742       Fax:  301-314-9661